The portreserve utility prevents RPC services taking specified privileged TCP ports. It does this by reserving them at boot, and provides a mechanism for releasing them on demand.

This is important for non-RPC services which require privileged ports, such as CUPS.

The portreserve package has been accepted into Fedora and the cups package has been modified to use it.

All that remains is to identify the services that should use it and to adjust their initscripts. The packaging guidelines may need updating as well, so that future packages that use portreserve do so consistently.